1. Field of the Invention
This invention relates to a device for adjusting the length of a cable that transmits linear displacement of an actuator to a controlled component.
2. Description of the Prior Art
Patent document EP-OS 338,450 describes a device for adjusting Bowden cables. The device includes a stationary abutment surface contacted by a supporting sleeve, which slidably and nonrotatably receives a sheath end-piece and is connected to a locking sleeve having an internal locking surface. The locking surface meshes with teeth formed on the outer surface of the sheath end-piece as a result of its rotation relative to the supporting sleeve, thereby fixing the effective length of the sheath.
This adjusting device has the disadvantage that the locking sleeve connected to the supporting sleeve rests against the stationary abutment surface only when pressure is applied. Consequently, it can lift from the abutment surface if a tensile load acts on the Bowden cable sheath. Furthermore, the connection between the supporting sleeve and the locking sleeve, made by means of a multiple-coil spring, is relatively complex and insecure.
U.S. Pat. No. 4,869,123 describes a cable length adjuster in which a square slider passes through a housing, which supports a latch and a leaf spring urging the latch toward the slider. The latch has teeth suited to engage teeth on a flat surface of the slider. The adjuster is self-locking and has no provision for manually rotating the latch into position to engage the slider.
U.S. Pat. No. 4,669,330 describes a cable length adjuster having a pivoting threaded square slider connected to a Bowden cable. The slider passes through a housing having threads formed on an inner surface adapted to engage the slider threads when the slider is pivoted into alignment with the housing axis. This pivoting action results from rotating a lever that forces the parts into alignment against the force of a coiled spring.
The housing of the cable adjuster described in U.S. Pat. No. 4,658,668 includes an axial hole through which a threaded slider connected to the cable passes. When the cable length is to be fixed by the adjuster, a latch supported on the housing slides in a recess laterally into engagement between threads of the slider, thereby locking the housing and slider against relative movement induced by a coiled spring.